Description

The N7 imidazole nitrogen of purine nucleosides
is known to take part in non-Watson-Crick
hydrogen bonding and in metal chelation.
"Deleting" the N7 nitrogen by replacing
it with a CH group is a useful modification that
has been accomplished in DNA oligonucleotides using the phosphoramidite of
2'-deoxytubercidin, namely 7-Deaza-dA CEP.1, which was useful in showing
that N7 of dA is an important hydrogen bond
acceptor site for the endodeoxyribonuclease
EcoRI.

Alternate Name(s):

Description

G-Rich regions
in nucleic acids often display disrupted Watson-Crick base-pairing due to the
ability of dG and G residues to enter into non-Watson-Crick inter- and
intramolecular hydrogen bonding. A
solution to this problem is to replace the N7 nitrogen atom
on the guanine nucleobase with a CH group, obviating the possibility of hydrogen
bonding at that position. For studies on alternating d(G-C)3 and d(C-G)3 hexanucleotides containing 7-deaza-2'-deoxyguanosine or 8-aza-7-deaza-2'-deoxyguanosine (BA 0242) in place of dG, see: Seela, F.; Driller, H. Nucleic Acids Res.1989, 17(3), 901-910. We also now offer 7-Deaza-G CEP (BA 0323) for RNA synthesis.